Blue Smoke from Exhaust. Where To Start?

[garye]

I've got a 2005 BMW 745Li and am seeing blue smoke come from the exhaust. It's not that frequent, but getting to a point where I'm noticing it and want to fix it.

The only times I've seen it is typically after idling or moving slowly. For example; when I'm stuck on the freeway in heavy traffic and only moving at 5/10mph then stopping, then when the freeway finally opens up a bit and I can hit some decent speed, I will see a nice cloud of blue and white smoke as I put my foot down.

When I bought the car a couple of months ago, there was an oil leak from the engine compartment. It turned out to be the left and right valve covers. We also changed out the rubber seal that is beneath the alternator. No more oil leak from the engine compartment that drips to the ground. Shortly after that I did an oil change. I filled it up to the max fill line and now 5 weeks later, the dipstick is showing we're at about 1/2. No oil on the ground at all.

I've done some digging and a lot of people are saying it's oil burning off which is causing the blue smoke. Could be valve stems. Some people recommend using sea-foam to clear carbon deposits too.

Where should I start?

Is there anything I can look for from home before I take her into a shop?

Thanks for any help with this!
Gary

[AB Able Truck]

** Copied from my previous post - updated days/miles - be sure to check your CCVs **


My car (didn't pass smog & couldn't renew registration);
2006 BMW 550I – 92,000 miles – V8 (N62TU)
Smokes (white/gray ) – failed visual – Smog Report (15 mph – HC ppm Measured 91 – Max. 49)


Symptoms & history;
It used oil (approx. 1 qt. per 2-3 tanks) and I read the history of V8 valve stem problems (internet & local shop research), I was about to have the valve guide/stem seals replaced or drive the car off a cliff. But it didn’t have the classic symptoms of defective valve stem seals/guides. It also ran like a rapped ape (old school for ran great). I’m a heavy truck mechanic with old school car experience (35 years). The plugs were clean and the exhaust smelled funny, also the exhaust dripped clean water no matter how hot or long it ran. I pulled the intake throttle housing and noticed excessive oil. Replaced the (ccv) diaphragms in the valve covers (torn) & read up on the cyclone oil separator (like a Dyson vacuum). Because I wasn’t happy with the oil consumption & residue in the intake, I fabricated a sponge with screen for each valve cover vent outlet. This cleaned out the oil residue and I assume it will reduce oil consumption while allowing crankcase recirculation, but it did not solve the smoke problem. I pulled the spark plugs and stuck a camera down a couple plug holes. Yes, the top of the pistons were loaded with carbon. So I sprayed Sea Foam in each plug hole, followed by a shot of low pressure shop air to help spread it around the piston. I let it sit for an hour or so, then reinstalled the plugs. I topped off the fuel tank with high octane and added 12 oz. of CRC Fuel System Cleaner (part #05063) to the tank. 100 miles later and what a difference – no smoke or water dipping out the exhaust after warm up. I’m in love with the car again


**The valve stem diameter was increase at a production point (you would assume) to remedy the guide problem. I could't believe BMW would continue to use inferior stem seals after this change. My vehicle has now passed smog test & no longer smokes. I did have to run the proceedure twice before it lowerd the HC levels within specs. And I will probably do it 1 more time for good measure. It cost me $200 to fix compared to the $4000 > $5000 I was told it would take for a guide/seal replacement **


**** Day 25 - 1000+ miles later NO smoke or excessive water from tailpipe - It also **** Does not need any oil ****
For those of you seasoned mechanics replacing guides & seals - This worked for me - my vehicle - my situation - but I believe you should diagnose each vehicle on an individual basis - Regardless of BMW guide/valve stem history.


**Note: I need to give full credit to my 25 yr. old friend/mechanic/smog tech/neighbor for his insistence I try Sea Foam. He works on BMWs, Mercedes and other makes. I never heard of Sea Foam (we used Justice Brothers in my hay day) and I didn't believe it would solve my issue. Although it was my idea to soak the piston tops first before spraying it thru the intake. I'll also take credit for the sponge/foam/screen in the PCV hose idea. **

[02325]

sounds like you have failing valve stem seals. very common issue.

prev poster had another issue. Seafoam will not cure the valve stem seal leak issue.

[s14b23]

Yep if ccv are ok, then most likely it's your valve stem seals. Idk how it helped one guy to soak pistons bc it doesn't make any sense unless his ccv valves were leaking so much so it clogged rings so bad so it started smoking, but I think it's rare case.

[garye]

Thanks for the advice. Yeah, I think it may be the valve stems too.

Will check out the CCV valves. They seem cheap to replace, so will go ahead and order those up.

Gary

[AB Able Truck]

I don't know if mine was a rare case or what, but it worked. I've researched the issue wasting more hours then I can count or care to admit to. I've also checked into other vehicle makes & models to see if there could be some pattern related to direct injection and PCV systems. I found that quite a few vehicle forums have the exact same complaints dealing with smoke from the tailpipe. The difference between these forums and BMW forums is that they don't scream valve stem seals right off the bat. After eliminating the obvious (head gaskets etc.) - they discuss catch cans, fuel grade/additives, walnut blasting and carbon build up. There seams to be a detailed debate over fuels, additives and their ingredients (Chevron/Techron - BG - Sea Foam and others) You can purchase a key hole camera (or whatever you call them) from Harbor Freight for around $75. Pull some plugs and take a look at your piston tops. Check your CCVs and intake for excessive oil. The less oil you introduce to the combustion camber the better. I'm not saying you don't have a valve stem seal problem - I'm saying eliminate the obvious and least expensive first.

[02325]

I don't know if mine was a rare case or what, but it worked. I've researched the issue wasting more hours then I can count or care to admit to. I've also checked into other vehicle makes & models to see if there could be some pattern related to direct injection and PCV systems. I found that quite a few vehicle forums have the exact same complaints dealing with smoke from the tailpipe. The difference between these forums and BMW forums is that they don't scream valve stem seals right off the bat. After eliminating the obvious (head gaskets etc.) - they discuss catch cans, fuel grade/additives, walnut blasting and carbon build up. There seams to be a detailed debate over fuels, additives and their ingredients (Chevron/Techron - BG - Sea Foam and others) You can purchase a key hole camera (or whatever you call them) from Harbor Freight for around $75. Pull some plugs and take a look at your piston tops. Check your CCVs and intake for excessive oil. The less oil you introduce to the combustion camber the better. I'm not saying you don't have a valve stem seal problem - I'm saying eliminate the obvious and least expensive first.

You do realize that the only Direct Injected E65/E66 is the 760 v12 cars. the V8 cars are not DI. SO your info has in no way have anything to do with the OP car.

[AB Able Truck]

I'm not going to split hairs while trying to save posters money by opening their eyes. This attachment is a BMW Technical Service Bulletin - although I've been told they updated to using Walnut Blasting as a preferred method. I think the move had more to do with EPA regulations and Dealer customer retention then the success of a chemical repair option. (It's all about the money)

http://ww2.justanswer.com/uploads/n9...154025_BMW.pdf

[White94RX]

Valve stem seals leaking. For sure

[02325]

WOW being up an ancient TSB. I have some of that fancy fuel injector cleaner in my garage. I will say the BG stuff is better.

OP, you need valve stem seals. no way around about it.

[AB Able Truck]

WOW being up an ancient TSB. I have some of that fancy fuel injector cleaner in my garage. I will say the BG stuff is better.
OP, you need valve stem seals. no way around about it.

Ok here's another one;
http://www.shipkiller.com/SI%20B%201...ust%202010.pdf

Please post a TSB from BMW or any published article related to smoke caused by bad valve stem seals. I can find numerous TBS and articles pointing to carbon build up troubles but I only find here say comments posted on forums condemning valve stem seals.

[PfDoug]

Blue smoke is oil burning. The combustion chamber cleaners, like seafoam, will clean up the buildup and burn it off. That's actually how you know it's working; the car will blow a huge plumb of blue smoke out the tail pipe as the old crud is burned out the exhaust.

Constant blue smoke, however, indicates the oil is leaking through the exhaust valves at idle. That's why the standard diagnosis is valve stem seals.

[bmwoem1]

I have a real fix for you guys....http://www.bimmerfest.com/forums/sho...09#post7554509

[AB Able Truck]

There are people on these forums that make a lot of money fixing cars on the side - Claiming they'll do the repair for a lot less at their home (usually for cash - you not knowing what was actually repaired). They may also convince you that your car needs an expensive repair so you may sell it to them at a discount rate, then they flip (resell) the car for a tidy profit. Some of these posters are easy to spot - Just search their postings and you'll see some actually bragging about the profit they made on a car they flipped. Others are hard to spot - They have several screen names - They'll even compliment their own honesty & work between their own screen names to boost their reputation.

Just be smart & use common sense - Research the issue - Don't believe everything you hear or read - Knowledge is power

[bmwoem1]

I hope your not I implying that I'm one of these people. My track record speaks for itself... Never a negative feedback because the cars actually get fixed the correct way and at a considerable savings to the owner.

[Carguy34]

Does this issue affect the V12's at all? Obviously if the valve stem seals are leaking they need to be addressed. My question is actually regarding how common the problem is on the 12's or if it is primarily a concern for the V8 cars.

[02325]

AB still avoids my question to him about he thinks his car is DI and not conventional EFI.

BMWOEM1 - I am glad someone on here is offering this service at a more respectable price over any shop. I will say I left BMW about the time we started seeing this issue roll into the shop. I have never done one or even seen one taken apart.

[AB Able Truck]

AB still avoids my question to him about he thinks his car is DI and not conventional EFI.

You might want to re-read what I wrote - And I asked you for some documentation on valve stem seals.

[QUOTE] I've also checked into other vehicle makes & models to see if there could be some pattern related to direct injection and PCV systems. I found that quite a few vehicle forums have the exact same complaints dealing with smoke from the tailpipe. [QUOTE]

- - - Updated - - -

Does this issue affect the V12's at all? Obviously if the valve stem seals are leaking they need to be addressed. My question is actually regarding how common the problem is on the 12's or if it is primarily a concern for the V8 cars.

This affects all vehicles with inefficient PCV systems and the fuels/emission systems of today (just check other make and model forums - not just BMW)

Engine PerformanceAutospeed published 8/18/2009 Issue 554


Almost without exception, commercial petrols would build up deposits on the components of an engine's intake system over time if they weren't additized. A number of additives have been developed which prevent and/or remove intake system deposits. Unfortunately, some of them increase combustion chamber deposits, solving one problem, but creating another. Since all base petrols are formulated to the same regulated specifications, the performance of the deposit control additive is one of the few features that differentiates one brand of petrol from another.


* Fuel Injectors and Carburetors
Fuel injectors are designed to accurately meter fuel to the engine and to deliver it in a precise pattern of fine droplets. Because the fuel passages are small, injectors are highly sensitive to small amounts of deposits in the critical regions where the fuel is metered and atomized. These deposits can reduce fuel flow and alter the spray pattern, degrading drivability, decreasing power and fuel economy and increasing emissions. Deposits cause similar problems for carbureted engines because carburetors also use a number of small channels and orifices to meter fuel. Port fuel injector (PFI) deposits are believed to form during the hot soak period after the engine has been turned off. The stationary petrol trapped in the injector is exposed to a higher temperature for a longer time than the petrol which flowed through the injector when the engine was running. The heat degrades the petrol, initiating deposit formation.


* Intake Valves and Ports
Intake valves and ports are subject to more deposit build up than fuel injectors because they operate at higher temperatures. Heavy valve and port deposits reduce maximum engine power because they restrict airflow. Intake valve deposits also have been shown to affect exhaust emissions. In some very sensitive modern fuel-injected engines, low levels of intake valve deposits can degrade cold start and warm-up driveability. Other valve deposit problems include valve sticking in very cold weather - because deposits interfere with the valve stem sliding in its guide, and burned valves - because severe deposits prevent the valve from seating properly.


* Combustion Chamber
When an engine is brand new, its octane number requirement is determined by its design and the quality of its manufacture. Generally, it will not knock when operated on petrol with the antiknock quality prescribed by the manufacturer. However, the engine's octane requirement increases as combustion chamber deposits form during the first several thousand kilometers of operation. If the increase is large enough, the recommended petrol octane rating may not prevent knocking or, if the vehicle is equipped with a knock sensor, the loss of power which accompanies knock suppression may occur.


Combustion chamber deposit interference (CCDI) is a new problem that has occurred in a few modern engines. It is the result of physical contact between deposits located on the piston top and cylinder head and is manifested as a very loud banging sound when the engine is cold. CCDI is limited to the engines which have been designed, primarily to reduce emissions, to have minimal clearance -1 millimetre or less - between some areas of the piston top and the cylinder head (squish areas) when the piston is at top dead centre. Deposits contribute to CCDI, but poor control of manufacturing tolerances in the susceptible engines also can be a factor. CCDI occurs primarily at cold-start. The interference and the telltale sound disappear as the engine warms up and the thermal expansion of the various engine components increases the clearance between the piston top and head at top dead centre.


Historical Development of Deposit Control Additives


* Carburetor Detergent
This class of additives consists of relatively inexpensive low-molecular-weight surfactants used at low concentrations. When introduced in 1954, they were effective in preventing and, in many cases, removing deposits from carburetor throttle bodies. However, they could not handle deposits in other parts of the carburetor, like the air bleeds, or in the rest of the engine intake system. The introduction of PCV and EGR emission control systems in the 1960s and 1970s increased deposit levels in the whole intake system. As a result, carburetor detergents were not as effective as they were in the simpler 1950s vehicles.


* Detergent-Dispersants
This class of additives consists of polybutene succinimides. Additives with similar chemistry had been used widely as engine oil dispersants before the chemistry was applied to petrol in 1968. Detergent-dispersants are used at concentrations three to five times higher than carburetor detergents. Their performance is sometimes improved by using them in combination with a petroleum carrier oil. They provide keep-clean performance for the intake manifold and intake ports. But they don't control intake valve deposits and have poor carburetor and fuel injector clean-up performance.


* Deposit Control (DC) Additives
The first additive of this class was introduced in 1970. It was based on polybutene amine chemistry and was used in combination with a carrier oil. While they have to be used at higher concentrations than detergent-dispersants, DC additives provide benefits throughout the engine intake system. They clean-up - and keep-clean - the throttle body and upper areas of the carburetor, fuel injectors, intake manifold, intake ports, and intake valves.


Lead salts are a combustion catalyst for carbon, so the shift to unleaded petrol changed the nature of combustion chamber deposits. When the first generation DC additives were used in unleaded petrol, they continued to control intake system deposits, but increased combustion chamber deposits. In response, a second generation DC additive designed specifically for use with unleaded petrol was developed and introduced in 1980. It was based on new polyether amine chemistry, which provides excellent deposit control performance throughout the intake system without contributing to combustion chamber deposits or causing any other adverse side effects.


* No Harm and Compatibility
DC additives are used at concentrations which are twenty to fifty times higher than the concentrations of other petrol additives. At these higher concentrations, they have the potential to affect petrol properties, fuel system materials and engine oils. So DC additives are tested for the absence of negative attributes (no harm) as well as for the positive attribute of controlling deposits. The additized fuel must be fully compatible with the elastomers and metals it will contact. Also it must have good water tolerance and not contribute to spark plug fouling or crankcase sludge formation.


* Required Additive Use
Because of the relationship between decreased deposits and decreased emissions, all motor petrol sold in the United States must contain an additive which provides a minimum level of deposit control performance. This requirement was established by the Clean Air Act Amendments of 1990 and became effective in January 1995. A similar requirement has been in effect in California since January 1992. Additive manufacturers are required to obtain EPA certification for their additives. The certification request must include documentation of the additive's effectiveness in specified fuel injector keep-clean and intake valve keep-clean tests and the additive concentration at which this performance is achieved. Certification may be obtained for use nationwide, for use in specific areas of the United States, or for use with particular types of petrol. Nationwide certification requires using a test petrol which meets ASTM D 4814, but has a greater tendency to form deposits than the average petrol.


Petrol formulators must add a certified deposit control additive to their petrol at the certification concentration level or higher. Over some range, higher concentrations often provide improved performance; for instance, changing keep-clean performance to clean-up performance. Historically, some petrol brands have provided much higher deposit control performance than the certification performance required by the EPA. For competitive reasons, they probably will continue to do so.


* Aftermarket Additives
Aftermarket additives are additives intended to be added by the customer to a petrol (or oil) which is already in the customer's vehicle. Engine deposits are affected by engine design, driving conditions, petrol base fuel quality, and petrol additives. While all petrol must contain a deposit control additive, some additives are less effective than others or are used at concentrations which are less effective. In addition, some vehicle designs form heavier deposits than others, and some vehicle designs are extremely sensitive to deposits which do form. Aftermarket deposit control additives are available which can clean-up deposits which have formed due to these circumstances. Treating one tankful of petrol with the aftermarket additive is often sufficient. However, additive chemistry and dosage play large roles in determining the effectiveness of the product. Polyetheramine-based aftermarket additives have been shown to be particularly effective at providing excellent intake system and combustion chamber deposit clean-up.


Additional info;
http://www.shipkiller.com/SI%20B%201...ust%202010.pdf
Last edited by AB Able Truck; 07-09-2013 at 03:21 PM. Reason: Additional info

[bmwoem1]

I have yet to see this on a V12. I'm not saying it doesn't happen, it's just those engine are not as common. I would say most N62 and N62tu's with over 80k miles have a valve stem issue in some degree.

[AB Able Truck]

I have yet to see this on a V12. I'm not saying it doesn't happen, it's just those engine are not as common. I would say most N62 and N62tu's with over 80k miles have a valve stem issue in some degree.

You work for a dealer - Can you provide any BMW or other documentation related to bad valve stem seals. I'd even appreciate an old TSB on bad valve stem guides. Also, if you're just replacing seals - and the customer has a guide problem - isn't that just putting a band-aid on a wound that won't heal?

[bmwoem1]

There isn't any bulletin on valve stem seals. Reason being.... Bulletins are put together to aid in the warranty repair period (4 years/50k). They will not spend the time/money to put together a TSB that will only address older vehicles out of warranty such as all these valve stem seal issue vehicles. Also, the valve guides can easily be checked for excessive wear. If it is determined that the guides/valve stem are worn, then the heads would need to go to a machine shop.

[02325]

I noticed this more and more with BMW before I left. BMW in a way could care less in what happens to the vehicle after the warranty period has run out. So that is why there is no info from BMW on this issue. I even asked my friend that still works at my local dealer and he hasn't seen/heard any one from BMW mention this issue.

[White94RX]

I love replacing them! I'm doing my tenth set in the last few months. I would do these and nothing else at work if I was able to. N62's and N63's

If you're near Atlanta and want them done, come see me at United BMW Roswell.

[bmwoem1]

The N63's that you're doing the stem seals on, what is the oil consumption rate? At what mileage have you been replacing them at?

[White94RX]

All the N63's have been in the 45-60k range. Much earlier than N62's. They were burning maybe a quart every thousand miles. One of the X5's even had lots of black soot on the bumper around the tail pipes.